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Air Force Gives 10-Year-Old Orbiting Satellite To Ham Radio Operators (arrl.org)
Longtime Slashdot reader Bruce Perens writes: The U.S. Air Force has transferred control of a 10-year-old orbiting satellite to AMSAT, a ham radio organization, which has enabled it for any licensed ham to use on the air, as the satellite's Air Force missions have ended. Falconsat 3's first mission was science: measuring gravity gradient, spectrometry of the plasmasphere, electronic noise in the plasmasphere, and testing three-axis attitude control using microthrusters. Secondarily it was used to train Air Force Institute of Technology students in space operations, with close to 700 cadets obtaining ham licenses in order to operate a number of Air Force satellites using ham frequencies.
Now in its third mission, control of the satellite has been transferred to AMSAT, the Radio Amateur Satellite Corporation, and all government frequencies have been disabled with only ham ones remaining. The satellite will relay APRS (position and status reporting) signals, it will operate a BBS in the sky, and will broadcast telemetry.
Now in its third mission, control of the satellite has been transferred to AMSAT, the Radio Amateur Satellite Corporation, and all government frequencies have been disabled with only ham ones remaining. The satellite will relay APRS (position and status reporting) signals, it will operate a BBS in the sky, and will broadcast telemetry.
The "FalconSAT" name certainly suggests a link to SpaceX's Falcon 9 rocket, but it is actually unrelated, predating SpaceX's founding. The satellite series has used a number of different lift vehicles - FalconSAT-3 used an Atlas V 401 rocket, as part of a multi-satellite launch.
The closest the two Falcons came was the launch of FalconSAT-2, which got bumped from the Space Shuttle's manifest after Columbia. It got re-used as the payload on SpaceX's first-ever launch, the first Falcon 1 flight. Which failed catastrophically a half-minute in. The satellite apparently survived with "minor" damage, falling back onto the island, but it was never re-launched to my knowledge.
The Air Force probably doesn't need FalconSAT-3 anymore because they have FalconSAT-5, which presumably can fill a similar purpose.
Falconsat 3 was built at the air force academy, not the AF institue of technology. '06 grad here. just google it -
https://www.google.com/search?rlz=1C1GGRV_enUS750US750&{google:acceptedSuggestion}oq=falconsat+3&{google:instantFieldTrialGroupParameter}sourceid=chrome&ie=UTF-8&q=falconsat+3&pws=0
Can anyone explain why the uplink is in the 2m band while the downlink is in the 70 cm band? Having separate frequencies makes sense, but what purpose is there to having them this far apart?
How is the Riemann zeta function like Trump rallies? Both have an endless number of trivial zeros.
AMSAT on the bottom of this page specifies 3 programs as "Software for operating via the Packet BBS". But I see that at the moment it is open for live QSOs but not automated ones.
Bruce Perens.
Deep breath.. No need to make this political... yet...
AMSAT does handle orbit control for its own satellites, but in general no ham radio satellite is designed to de-orbit or to require periodic orbit maintenance. Rather, they are designed to operate with indefinite lifetimes in slowly-decaying orbits, and AO-7 has operated, with interruptions, for 43 years. Most Amateur satellites are passively stabilized, and magnetic stabilization systems have been used often.
Bruce Perens.
I broke the ARRL web site :-). Try the AMSAT site instead.
- K6BP
Bruce Perens.
Not sure whether to be more concerned at the fact that there is a 10-year-old locked in orbit around a satellite, or that control of said youngster is being transferred to a ham radio organization.
Strange...
Since the AF disabled the S band and other transponders, one of which was probably for command and control, the capability of controlling it, if there was any way at all, is gone. After 10 years, I doubt that there is much in the way of orbital maneuvering that can be done, in any case. For small sats like this, they may have had a small amount of gas initially in order to place the thing into the proper orbit after launch but that probably ran out years ago. I'd suspect that the bird is fixed in its orbit and will only change if the orbit begins to decay and it eventually re-enters the atmosphere and burns up. Not much can be done about that.
I wonder if this was accelerated because of the need for HAM operators in Puerto Rico following Maria.
Your ad here. Ask me how!
The real requirement was that the satellite not transmit on those frequencies. There isn't any problem with receiving. A satellite with this size and cost is often built without ROM, simply because of the cost of space-qualified ROM which must be rad-hard for decades of operation. It loads its computer program into RAM using a completely hardware implementation driven by ground control with the CPU reset line asserted for the whole time. Once the program is loaded, the CPU is allowed to start. The CPU may be horribly antique by today's standards due to the need for silicon-on-sapphire for rad-hardness. Satellites of that age could even be using the 1802, as that was one of the few CPUs we could get in silicon-on-sapphire and AMSAT-DL (Germany) wrote an embedded OS for it.
So, the big switch from Air Force operation was likely a reload of the software, and AMSAT is probably now in control of that software. It is likely that the satellite can be reloaded from multiple frequencies, and the "encryption" used to do that is rudimentary. A computer system designed this way is harder to kill than one that requires the CPU to load a program.
Bruce Perens.
Great, they get a beat up trainer. Seriously though, I'll bet a lot of those cadets go on to train for volunteer emergency communications later on.
If you would like to be a ham, go to this page and fill out the form. The folks at ARRL will send you information on becoming a ham. Also, read this part on getting licensed.
There is a lot more to it than CB, and a lot of the stuff you hear on CB shouldn't ever be done on ham radio. And ham radio is not a gift. Expect to do some work to become a ham.
Bruce Perens.
3840 kHz will sure get him a mix of ham and CB.
Strange things are afoot at the Circle-K.
There's no such device, at least not in the US. Under FCC rules a radio for use on CB (11-meter band,) has to be type certified and channelized. Ham radios operate all across the amateur spectrum, (160-meters through 10-meters on HF, 6-meters through 2-meters on VHF, etc.) and require no type certification. Since a legal CB radio must only operate on CB channels, and a ham radio lacks type certification, the two services are mutually exclusive, as far as equipment is concerned. The one exception is that every HF ham radio I've seen can receive on the CB channels, but will in turn refuse to transmit, (so as to remain legal.)
I'd recommend getting your amateur license. The technician's, (or even general,) exam is easy, it's a lot of fun, and it gives you a chance to give back to the community in the form of supporting emergency communications, if that's of interest to you.
It loads its computer program into RAM using a completely hardware implementation driven by ground control with the CPU reset line asserted for the whole time. Once the program is loaded, the CPU is allowed to start.
I'm not sure what you mean here, but it sounds really cool. Could you clarify? Plz? :)
"First they came for the slanderers and i said nothing."
Is that something William Shatner is involved in?
These are probably better than my explanation. A German space scientist, Karl Meinzer, designed this all in the 1970's and it's still being built into satellites.
Bruce Perens.
>the two services are mutually exclusive, as far as equipment is concerned.
And usually Hams wouldn't touch a CB rig with a 1000000000000000000 foot pole.
"If you ask me that ain't no rose, roll up your windows and hold your nose." Leyton Wainwright III
It looks like the FOX series of low-earth-orbit cubesats are using STM32 and GNU C. Here's a slide show. Because these don't traverse the van Allen belt, they don't have to be as rad-hard as higher-orbit satellites.
Bruce Perens.
New amateur receivers are type-certified for avoidance of the old 800 MHz analog cellular frequencies, as required by the Electronic Communications and Privacy Act in 1986. So, you will see a notice about radios not being offered for sale until they are type-certified.
I would like someone to help work on repealing that provision of ECPA. Obviously everyone uses encryption now.
Bruce Perens.
Which satellite are they orbiting?
You can't take the sky from me
I especially liked the sentence about the 'three-axis attitude control'.
"Trump!!", the new Godwin.
In order to qualify as a legit BBS, it has to have TW2002...
Thanks for posting this up Bruce, it's a wonderful story.
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
I Look forward to hearing what the Ham Radio guys do with it
Build a Man a Fire, and He'll Be Warm for a Day. Set a Man on Fire, and He'll Be Warm for the Rest of His Life.
The 1802 was pretty popular CPU for military use in the 70s-80s. Not just for space use. God, I remember that, wow.
deleting the extra space after periods so i can stay relevant, yeah.
There is still no requirement that amateur transceivers must be type certified for use in the Amateur Service. An Amateur radio operator can build their own radio and use it all they want, provided they adhere to emissions standards. But, they do not have to obtain type certification to use their radio.
A satellite with this size and cost is often built without ROM, simply because of the cost of space-qualified ROM which must be rad-hard for decades of operation.
I thought it was the other way around? A PROM, and especially a mask ROM is an incredibly simple device, effectively just a single diode between a given row and column on the die. Not counting the address decoder (which you would have in both RAM and ROM), a ROM chip only has a single PN junction per bit. An SRAM cell has 6 transistors per bit, and DRAM is a capacitor plus a transistor (not to mention the required refreshing).
I'd love to be shown the error of my ways, but I would have thought the KISS principle would hold.
...si hoc legere nimium eruditionis habes...
However in order to be sold in the USA, they must comply with the law that forbids reception on the old AMPS bands. Of course, this is usually just a pinkyswear on the part of the manufacturers, and can be unlocked either through accessing a calibration mode, or by snipping a diode/resistor on the main circuit board.
...si hoc legere nimium eruditionis habes...
You can build one, but you can't sell a VHF/UHF transceiver that is not type approved, because all receivers in VHF/UHF bands are considered to be scanners, and thus must be type approved. It's not in Part 97 but elsewhere in FCC regulations.
Bruce Perens.
The point is that you can't sell the radio without FCC approval. This concerns me because I am producing an SDR radio that is supposed to be 100% Open Source, but in order to sell it as anything but test equipment, I need to have one little non-Open-Source part that keeps the receiver from being programmed to receive AMPS cellular.
Bruce Perens.